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Date: Thu, 20 May 2010 10:52:58 -0500
From: Anthony Liguori <anthony@codemonkey.ws>
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Subject: [Qemu-devel] Re: [PATCH 0/6]: QMP: Fix issues in parser/lexer
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To: Paolo Bonzini <pbonzini@redhat.com>
Cc: aliguori@us.ibm.com, qemu-devel@nongnu.org, Luiz Capitulino <lcapitulino@redhat.com>

On 05/20/2010 10:18 AM, Paolo Bonzini wrote:
> On 05/19/2010 11:43 PM, Anthony Liguori wrote:
>>
>>> 4. Lexer expects a 'terminal' char to process a token
>>>
>>>     Which means clients must send a sort of end of line char, so 
>>> that we
>>>     process their input.
>>>
>>>     Maybe I'm missing something here, but I thought that the whole
>>>     point of writing our own parser was to avoid this.
>>
>> If the lexer gets:
>>
>> "abc"
>>
>> It has no way of knowing if that's a token or if we're going to get:
>>
>> "abcd"
>
> Only } and ] are valid characters at the end of a JSON object, and 
> neither requires lookahead.

Having look ahead operate differently for different states really 
complicates the lexer.  I don't see this as a big problem in practice.

Regards,

Anthony Liguori

> Paolo